Reversible tooth for earth digging equipment



Sept. 13, 1960 G. A. M. PETERSEN 2,952,035

REVERSIBLE TOOTH FOR EARTH DIGGING EQUIPMENT Filed Sept. 9, 1957 3Sheets-Sheet l INVENTOR.

3/ Gerald A. Petersen Sept. 13, 1960 a. A. M. PETERSEN 2,952,085

REVERSIBLE TOOTH FOR EARTH DIGGING EQUIPMENT Filed Sept. 9, 19s? 3Sheets-Sheet 2 INVENTOR. 663410 ,4. PfIZ'AiSZ-W BY K/Z Q p 1950 5. A. M.PETERSEN REVERSIBLE. TOOTH FOR EARTH DIGGING EQUIPMENT Filed Sept. 9,1957 3 Sheets-Sheet 3 INVENTOR. GERAlD 14.??5!

Imam? Patented Sept. 13, 1960 REVERSIBLE TOOTH F OR EARTH DIGGINGEQUIPMENT Gerald A. M. Petersen, P.O. Box 330A, Santa Clara, Calif.

Filed Sept. 9, 1957, Ser. No. 682,720

The terminal portion of the term of the patent subsequent to Mar. 17,1976, has been disclaimed 13 Claims. (Cl. 37-142) This invention relatesto a new and improved reversible tooth for earth-digging equipment, suchas earth angers and the like. At the present time earth-diggingequipment of various types employs a plurality of digging teeth whichabsorb much of the wear encountered by the tool and also are the portionof the equipment most likely to be broken. The present invention relatesto a replaceable tooth for earth-digging equipment which is convenientlyand rapidly replaceable and which further may be reversed so that whenthe tooth is worn on one side, it may be turned over and used on theother side.

This application comprises a continuation-in-part of my co-pendingUnited States patent application Serial No.

620,291, filed November 5, 1956, now Patent No. 2,877,- 574, forReversible Tooth for Earth-Digging Equipment. Accordingly, one of theprincipal objects and advantages of the present invention is theprovision of a tooth which may be attached to and removed from a shankplate or other portion of an earth-digging tool or other piece ofsimilar equipment with a minimum of time and effort.

Another object and advantage of the invention is the provision of areversible tooth which may be used first on one side and, when worn, maybe turned over and used on the other side. One of the particularfeatures of the invention is the facility with which the tooth may bereversed and, after having been reversed, securely locked in positionwith a minimum of labor and without the use of special tools orequipment.

Still another feature of the invention is the provision of cooperatingmeans on the tooth and shank plate or other portion of the equipment towhich the tooth is attached, which assist in securing the tooth inplace.

A still further feature of the invention is the provision of cooperatingmeans on the tooth and shank plate to which it is attached, whichprevent the tooth from being displaced from its proper position when thetooth is subjected to severe stress, such as striking a hard object atone corner of the tooth.

One of the principal advantages of the instant invention is the factthat wear of the tooth occurs on its edge. In other forged replaceableteeth, the means of connection employs a stud and a socket. Wear occursin the zone of connection between the stud and socket, which isparticularly subject to abrasion and other frictional deterioration.Since the socket is conventionally a permanent part of the earth-diggingequipment, deterioration of this part of the connection causes discardof the equipment, thereby defeating a primary reason for the use ofreplaceable teeth. The instant invention eliminates the socket principleand the tooth is wide enough to protect the underlying shank from wear;hence the shank is truly permanent and need not be replaced despitewearing out of many replaceable teeth.

Another object of the invention is to provide means whereby a tooth isformed having a slot extending forwardly of the proximal end thereof,which divides the tooth into two discrete portions at the proximal end.A

shank is provided having a step or recess shaped to receive at least aportion of the proximal end of the tooth and, further, having meansextending through the slot and engaging the edges of the slot to holdthe tooth in position in the shank. Further, the tooth and shank may beprovided with cooperating means in the form of mating depressions andprotuberances or other means hereinafter described in greater detail,which cooperate to prevent withdrawal of the tooth from the shank priorto the time when it is desired to reverse or replace the tooth.

An important feature of the present invention is the fact that the toothis held in a shank and the shank is secured to the major piece ofequipment, such as an auger, so that the tooth and even the shank may bereplaced when worn or damaged, without the necessity of discarding themajor piece of equipment.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawings,in which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

Fig. l is a perspective view of a portion of a piece of earth-diggingequipment,- such as an earth anger, with a plurality of teethconstructed in accordance with this invention attached thereto;

Fig. 2 is an enlarged sectional view taken substantially along the line-2-2 of Fig. 1;

Fig. 3 is an enlarged top plan view of a tooth and a portion of theadjacent shank;

Fig. 4 is a sectional view taken substantially along the line 4-4 ofFig. 3;

Fig. 5 is a view similar to Fig. 2 of a modified tooth;

Fig. 6 is a top plan of the structure of Fig. 5 with the bolt headremoved;

Fig. 7 is a fragmentary view of a modified structure similar to thatshown in Fig. 5;

Fig. 8 is a view similar to Fig. 2 of a modified tooth;

Fig. 9 is a side elevation of the tooth shown in Fig. 8;

Fig. 10 is a top plan thereof;

Fig. ll is a view similar to Fig. 2 of a further modified toothconstruction;

Fig.12 is a top plan of the tooth shown in Fig. 11.

The present invention relates to a reversible replaceable tooth 11. Asshown in Fig. l of the accompanying drawings, a plurality of such teethmay be attached to a piece of earth-digging equipment, such as an earthauger 12 of the type used to dig holes for utility poles. Reference ismade to United States Patent No. 2,578,014 which illustrates an earthauger to which the present invention may be attached. As an integralpart, or, as shown in the accompanying drawings, a separate part of suchequipment, there is provided a shank p1ate'13 attached to the mainportion of auger 12 by means of bolts 14. The shape of shank plate 13varies considerably and the number of teeth 11 attached thereto islikewise the subject of variation. As illustrated in Fig. 1, one suchshank plate 13 provides a means of attachment for three teeth 11, theattachment means for each tooth being substantially identical.Accordingly, the attachment of a single tooth to the shank plate will bedescribed.

Shank plate 13 is formed with a plurality of outwardly projecting roots16 corresponding in number to the teeth and disposed in a direction andat an angle to the axis of rotation of the tool which is determined byproper engineering design. The width of root 16 is substantially thesame as the width of tooth 11 and the length of the root is sufiicientto form a secure attachment. Each root 16 is cut away in a step having aback wall 17 substantially perpendicular to the direction of the toothand a bottom wall 18 substantially parallel to the direction of f jProjecting upward from bottom' wallilifare three pro? JItuberanceslhil;122; (The two prothherances 2.1 am; located inwardlyof'the central *axisof aperturet19 and to either side thereof, and thethird protuberance 22 located midway ofthesides oi therootand; forwardlyjofaperturekl9. 1 'flProtuberances21,122 are of a shape" Yandhave'afunction ashereinafterdescribed. 'f

absorb wear andlgwithstand shook. {)Toothll 'is of bstahtia lly the samewidth? throughong havingparallel side" edges26 atleastat itsproximalendg The distal faces;

,2'7pf1thetooth taperlat an angletof approximately 6 Ihreplacedbr:resharpenedp; [The proximal .of the to'othhas {substantiallyparallel top andbottom faces 31 and-32- and j rearendwah 33perpe'ndi'cnlar'to faces '31'andi32 and r forwardly from ,rear end; wall331 of the toothandthe lengthf of slot 34 is'fsuchthaLiwhen aearriagetboltfiti isl i inserted 111 the 'slot 34 and through aperture.19 tooth ,11 is properlylocated in,position. j j f "Bothathe top andbottom. proximal faces 31; and 320i ")6 y .thetooth' are formed -w'iththree"depressionsfily ll, 42 corresponding'in positionto thethreeprotnherancesczl, 1 .21, 22 on shank plate13. Asshownhr Fig. l4and'con- Tsidering the depression 541 111; the top proximal face 31, each ofthe rearward disposed depressions 41' 'extend's'i 26.?The forward wall43 of depression 41*slo' msv down;

' wardly-re'arwardly at an angle ofg'approxirnately 153 commencing'along ajline displaced rearwardly I returns 44 of bolt .36ashortdistance. '-Tharea 1i.4ei

of the depression slants downwardlyforwardlyatan angle 545,? andintersects,foiwardwall43toptOide a max mum depth or the depression as--indicated by referenc I numeral 47) approximately one quarter thethickness of .thGtOOth. Z V

I approximately one-quarter the thickness of theitooth;

, mate'lyf 45j 4,, or

i has been stated, positioned andfsh'aped to fit snugly with bprotuberance s ZIon either side areforrned extendin iii-n 1 'wardly fromside edges 26 a distanee equal tto thevviclth.faee'figl--ofprotuberance21 is disposed at an angle of with respect tohottom wall l3,uand front face 52 slants downwardly-forwardly at anangle of substantially I in seating of the tooth.

The width of slot 341s equal to the Width of s uare neck the V'tooth.The, root, is termed an 7 aperture 19 extending through bottornjwall'18'hdiacent' the outerend of the iroot 'and centrallylocatedrelativetothe sides-f thereof;

Tooth 11 formed ofahardpieceof metalsoasto and aretmncated tofonn aforward end 28, therehy providing affirst.andyasecondseuttingedge 29 on,oppo site .faces of *thegtooth; ,,Oneof the advantages of the' presentinvention is the fact that the; tooth: may be used with one face upwardand then reversed so that twice the'wear may be obtainedjbefore; thetooth, need? be I 2' sideedges 26. .Back end wallf33of the] toothseatsagainst I back Wall 17 of the step. rectangnlarfslot '34hextends Facrosswthe width. of'the toothfrom fslot'34 to side edge? tromthe'eena.1'

Forward depressionf42-hasa" width slightly greater than one-quarter thewidthof tooth 1'1 and has a depth i Forward depression 42 1s centrallydisposed with respect to side edges '26 of the tooth andextendsforwardly of forward wall'48 Of SlOt34 substantially horizontally adistance;substantially-equal to the widthof" depression f .425; Theforward wall ,49 of depression 42 (as; Shown in'Fig. '2 and consideringthe depression! 42; in top' fajceq Y 31) I slopes upwardly-forwardly atan angle (of approxb; J

; Protuber a ces 2 1,f21," 22 3011 1 shank plate, 13 aregasil q I i indepressions 41; 41; 42. :Accordinglythe rearward between slot 34 andedge 26 oftoothf11. The rearward f 15; Forwarduprotnberan'cen has awidthequal'to the) widthof forward depression 42 ontooth Hand a heightequalfto" the depth thereof extending forwardly -from' aperture 19, andits corner edges are chamfered to assist.

Tooth 11 may befattaohedtoshankplatefBby a earr'iagebolt" 36 having "asquare nec k ifi' under its head 57.

"feature of the invention materially s "the'tooth'orareplacing the same;

rornfbottom 1810f the'stepoflshank 16a; in a'position,

ence numeraI GSQ The pnr'poseof the" depression 65 is i fappliedgtofthefaces to'eitherside of slot 34 to seat I projections 21in grooves 41.It'willfur'therfbeseen that rather than b'eing of the same width.

t heinvention- Reference line fifi shows a representativew.

'ZOdigging 67 shows how, even with considerable wear of the "distalofthetooth, useful life thereof is maintained before the tooth needbereplaced.

torthatof Figs. 5' and 6 except for the fact'that only one 7 5 5 6nnderhead harnesses and hence two sides ofthex square neck engage theside edgesof slot,34' and v A i f a third side of; the neckseatsagainsttfiront wall48, of Y slot 34." WhennutSSlstightened onboltfifi, fhead57.

' hearsagainsttop face, 31 oftooth 11 and locks ltheftoothsnilglytoshank pla teli'a. The locking of the tooth to the shank 5 plateis accomplished by' the "cooperationof the parts as heretofore.described. Thus back face-33 f'toQth-IILe gagegbaek wall, '17OfSilfiIlkPlhillgLiand. f bottom facqliz'ofthe tooth engagesbottom wallllfi of j 1 shank plate 13. In addition; protuberances 21, 21;;221, Q fitinto depressions 41, .41, 42 and additionally neck; 56] 1 1 of boltf36engages the side and. frontwalls'of'slot 34.

In{ the event that toothll strikes a hardobjeet on one corner,protuherancesll, 21,12; assist in preventing the p I tooth'from' 'beingknocked out of alignment; inasmuch as they -resist any twistingrnovernentrofthe tooth.

It will be. seen. that, in order to remove a'tooth 11," v

it is not. necessary to remove nut 58 completely from T58 is loosenedsufficiently sothat protuberances 21,121, 22 r cleardepressioiis 41,.41, ,42; whereupon the tooth may e headrawn forwardly by reason, of thefact that; there is" bolt 36 r to removeholt 36, from aperture 19. T Nutprovided trslotl 34 insteadof'merely ya holt'hole. This plifiesreversing V v Afterthe' tooth has been used nntil one cutting edge29,,is' worn; the tooth is reversed; as has been indicated,

",iandfltheflother edge,-29 used. When the tooth must he s i replaeedorresharpened, the construction heretofore de- I'scribedexpeditestheseoperations. l

'c111sive,{ar'e similarin many respects to that form'showmf in Figs.1-4,.inclusiveyand accordingly, for purpose of and shank is'ao'mitted;correspondifig partsof the tooth 1 h eing given the same referenoenumerals in "the acc'om-;.

i l g drawi In Odifioation ,40

sions" 42 are eliminated. A protuberance 61 is formed extending'upinto;sloti34i'n a position ahead of neck:

hehindiholt head 56 and forwardly-"of rear wall 17. .Pro. t I it'j'ections 61; and 62 stabilize the tooth relative'to theshank i platehypreventing relative movement in any direction transverse to the axis ofthe bolt 3.6. It will be.understood that the width of projection 61' issubstantially 1 equal to the width of the slot 34, but, as illustratedin.

the forward wan of the slot.- .Itwill further'be observedfi 5hatforwardly of1slot'34; boththe top andbottom surfaces of the tooth aredepressed, as indicated by refer to insure that, when nut 58 is drawntight, the pressure. e

the outer end of the shank is turned up; as indicated port, shank. roots1611 i are rnade wider than thetooth, Fig. 5 illustrates oneof thefeatures and advantages of.

line of diggingwhen the tooth is new; whereas line of."

The modification of Fig: 7' is inmany projectionfirextends upfront thelfibso thatthei;

3 space behind neck 56 of bolt 36 isclear, in the same manner as isshown in Fig. 2.

Figs. 8-10, inclusive, are similar to the modification shown in Figs. 5and 6, except that the shape of tooth 81 differs. It will be understoodthat the shape of the tooth is subject to considerable variation. Thetooth shown in Fig. 8 is designed for trenching machines, The distalcorners 82 are beveled in top plan, and beveled facets 83 are formed atthe corners, as best indicated Fig. 10. It will be understood that othershapes of teeth may be employed in all of the modifications of theinvention. This manner of fastening tooth 81 to its shank is essentiallythe same as in Figs. 5 and 6. v

Figs. 11 and 12 illustrate a further modification of the invention. Theproximal top and bottom faces 87 of tooth 86 are roughened or knurledand similarly the bottom face 88 of the step of the shank is knurled orroughened. It will be understood, further, that only one of the twosurfaces 87 or 88 need be roughened, particularly when the tooth is notsubject to as severe stresses as the teeth of the previous modificationsare capable of absorbing. When the nut 58 is drawn tight on carriagebolt 36, the roughened surfaces grip against each other and preventdislodgment of the tooth. It will be understood that a slot 89 is formedextending forwardly from the proximal end of tooth 86 and that this slotcooperates with square neck 56 of carriage bolt 36 to hold the toothagainst displacement. The roughened surfaces 87 and 88 function in muchthe same manner as the projections 21, 22 and depressions 41, 42.

-What is claimed is:

1. A tooth for an earth-digging tool comprising a unitary, hard piece ofmaterial having a tapered distal portion and a proximal portion formedwith substantially parallel proximal external faces, said proximalportion being formed with a substantially rectangular slot extendingforwardly from the proximal end of said tooth for the reception offastening means in a direction transverse to said proximal externalfaces to form a pair of rectangular prongs, each of said proximalexternal faces being formed with a plurality of V-shaped depressionsextending transversely across the width of at least one external surfaceof said prong, a first of said depressions being located rearwardly ofthe inner terminus of said slot and to one side thereof, and a second ofsaid depressions being located rearwardly of the inner terminus of saidslot and to the side thereof opposite to said first depression.

2. A reversible tooth for an earth-digging tool comprising a unitary,hard piece of material having an outwardly tapered distal portiontruncated to provide a first and a second cutting edge disposed onopposite faces of said tooth, and a proximal portion formed withsubstantially parallel proximal external faces, said proximal portionbeing formed with a rectangular slot extending inwardly from theproximal end of said tooth to form a pair of rectangular prongs, theedges of said slot being substantially parallel to the side edges ofsaid tooth, each of the top and bottom faces being formed with aV-shaped depression extending transversely across the width of saidprong, a first of said depressions being located rearwardly of the innerterminus of said slot and to one side thereof, and a second of saiddepressions being located rearwardly of the inner terminus of said slotand to the side thereof opposite to said first depression.

3. A reversible tooth for an earth-digging tool comprising a unitary,hard piece of material having an outwardly tapered distal portiontruncated to provide a first and a second cutting edge disposed onopposite faces of said tooth, and a proximal portion formed withsubstantially parallel proximal external faces, said proximal portionbeing formed with a substantially rectangular, vertical slot extendinginwardly from the proximal end of said tooth to forma pair ofrect'angular prongs, the edges of said slot being substantially parallelto the side edges of said tooth, each of the top and bottom faces ofsaid prongs being formed with a depression extending transversely acrossthe width of said prong, a first of said depressions being locatedrearwardly of the inner terminus of said slot and to one side thereof, asecond of said depressions being located rearwardly of the innerterminus of said slot and to the side thereof opposite to said firstdepression, each of said first and second depressions being shaped witha rearward wall disposed extending forwardly inwardly at an angle ofapproximately 45 and a forward wall intersecting said rearward wallextending rearwardly inwardly at an angle of approximately 15.

4. In combination in an earth-digging tool, a shank formed with at leastone step therein having a rear wall anda substantially transverse bottomwall, said shank being apertured in said bottom wall, a plurality ofprotuberances on said bottom wall, a tooth formed of a unitary piece ofmaterial, the proximal of said tooth fitting into said step and abuttingsaid rear and bottom walls thereof, said tooth having a tapered distalportion and a proximal portion formed with substantially parallelproximal external faces, said proximal portion being formed with anaperture for the reception of fastening means in a direction transverseto said proximal external faces, at least one of said proximal externalfaces being formed with a plurality of depressions, a first of saiddepressions being located rearwardly of the inner terminus of saidaperture and to one side thereof, and a second of said depressions beinglocated rearwardly of the inner terminus of said aperture and to theside thereof opposite to said first depression, said protuberancesfitting into said depressions, fastening means passing through theaperture in the bottom wall of said step and through the aperture insaid tooth and cooperating with said protuberances and depressions tosecure said tooth to said shank against forces tending to twist saidtooth relative to said shank, and a projection on said shank extendingup into the forward portion of said slot ahead of said fastening means.

5. In combination in an earth-digging tool, a shank formed with at leastone step therein having a rear wall and a substantially transversebottom wall, said shank being apertured in said bottom wall, a pluralityof protuberances on said bottom wall, a tooth formed of a unitary pieceof material, the proximal of said tooth fitting into said step andabutting said rear and bottom walls thereof, said tooth having anoutwardly tapered distal portion and a proximal portion formed withsubstantially parallel proximal external faces, said proximal portionbeing formed with a slot extending inwardly from the proximal end ofsaid tooth, the edges of said slot being substantially parallel to theside edges of said tooth to define a pair of prongs, each of the top andbottom faces of said prongs being formed with a depression extendingtransversely across the width of at least one external surface of saidprong, a first of said depressions being located rearwardly of the innerterminus of said slot and to one side thereof, and a second of saiddepressions being located rearwardly of the inner terminus of said slotand to the side thereof opposite to said first depression, saidprotuberances fitting into said depressions, and fastening means passingthrough the aperture in the bottom wall of said step and through theslot in said tooth and cooperating with said protuberances anddepressions to secure said tooth to said shank against forces tending totwist said tooth relative to said shank.

6. In combination in an earth-digging tool, a shank formed with at leastone step therein having a rear wall and a substantially transversebottom wall, said shank being apertured in said bottom wall, a pluralityof protuberances on said bottom wall, a tooth formed of a unitary pieceof material, the proximal of said tooth fitting into said step andabutting said rear and bottom walls thereof, said tooth having anoutwardly tapered distal portion and a proximal portion formed withsubstantially parallel proximal external faces, said proximal portionbeing formed with a vertieal substantially rectangular slot: ex rtending inwardly iromfthe proximal end 'of said tooth to formalpair. ofrectangular prongsrthe edges of said slot;

formed with a depression extendingtransversely' across,

I asserts the width of said prong, a first ofsaid depressionsbeingtersecting said I rearward wall extending rearwardly' 111-,

I located, rearward1y1 of'the inner-terminus of said slot and to oneside, thereof, and a second of said depressions I being locatedrearwardly of the inner terminus ofsaid slot 5 and to the side thereofopposite tosaid first depressionr, 1 each of said, first and seconddepressions being shaped with a rearward -wall disposed extendingforwardly inwardly at an angle of approximately 45 and, a forward wallinfprises asecond protuberance extending up into said slot,

I behind said fastening means. f by I J i I 12; "In combination, in anearth-dig fag tool a unitary 15 wardly at an angle of approximately 15,saidprotuber- 'ances fitting into said depressions, and fastening meanspassing through the aperture in the bottom wall of said step and throughthe slotlin saidtooth andloooperating s with said protuberancesanddepressions to-secure said tooth to said shank against forces tendingto twist, said 1 tooth relative to saidshank.

7. In; combination in an earth-diggingtool, a shanlc formed: with atleast one step therein having a rear wall r g and" a substantiallytransverse bottom wall, said shank beingapertured insaid bottom wall, apluralityof promberances on said bottom wall; atooth vformed of aunitary f .piece ofrnaterial, theproximal of Said tooth fitting intosaidstep and abuttings-aidiear and bottom walls tamer,

said tooth having a distal portion tapering outwardly and a proximalportion formed with substantiallytparallelprox imal faces, said proximalportion being formed with a slot.

extending inwardlyfromthe proximal, end of said tooth,

the edgesof said slot being substantially parallel to the side edges ofsaid tooth, each ofsaid proximal faces being formed with" aplurality ofdepressions, :a first ofysaid depressions being locatedtrearwardly ofthe inner terminus of said slotand to onelside thereof, and a second ofsaid I depressions being located rearwardly of the inner terminus ofsaid slot and to the side thereof Qppositeto said first depression, saidprotuberances fitting into said depressions, p

and a carri age bolthavingasquare neckpassiug through t the aperture inthe bottom wall of said step and through 1 theslot' in said tooth, saidslot being dimensioned whereby" two sides of said neck of said bolt abut,thesides of said slot and athird side of said neck abuts the inner, endof said slot, said I bolt cooperating with said protuberances' anddepressions to secure said 'tooth'to' said shankagainst forces tendingto twist saidtooth relative to said shank.

8. In combination, in'anrearth-diggingtooh axuriitary i 1s.Thecornbination of claim 12, which and cam-j prises side depressions onsaid tooth on either side of said,

[R slot and'side protuberances. on said shank positioned to shank shapedto receive theprox-imal end of atooth, a;

tooth formed of a unitary piece of material and having i n proximalcndshaped to fit said shank, said tooth having,

top and bottom forwardlyconverging tapered distaltaces, i V

and a substantially rectangular proximal portion rearward 1 of saiddistal faces having substantially parallel top and bottom externalsurfaces and "a longitudinallyforwardly r extending, substantiallyrectangular slotj extending for-,1 wardly from the proximal end 0fsaidfltooth extending through from said top to'said bottomsurface anddividing said proxir'nal end into two discrete prongs: each substan'tial ly rectangular in shape, atleashone surface of: each i said prongbeing formed with a shallow depression ex-a tending transversely acrosssaid prong, and}means Carried by said' shank to restrain dislodgernentof "said tooth from said shank, saidlmeans engaging said depressions,said prongs being imperforate and no portion of said meansextendinginside said prongs.

Q9 The combinatiortof claimsin which as means extends through said slotdetachably holdingsaid tooth and shank in engagement with each other andinwhich said means comprises-1 cooperating meanson 'saidtoothi and shankto restrain dislodgement of said tooth from 'saidshank. I M r I whensaid fastening means-is inoperative.

ll. Thecombination of claim 10 whichturtheneomfl shank, shaped toreceive the'proximal end of a tooth, a

I tooth formed of a unitary piece of, material and, having I itsproximal end shaped to fitsaid shank, said tooth hav r topandbottomforwardly converging tapered distal I aces,;and asubstantiallyrectangular proximal portion A rearward 0i said distalfaces having substantially para-lleli s top and bottomsexternalsurfacesanda longitudinally forwardly {extending substantiallyrectangular slotextenda ingtrorn the proximal end ofisaid toothextending through from saidt op to said bottom 'surfaceancl dividingSaidff': proximal end-into two discrete prongs eachlsubstantially 1rectangular inwshape, and me'anscarried by said shank p to, restraindislodgmentrofi said tooth from said s hank', c

said {means engagingsjaid prongs, said prongs being imperforateandno,portionofzsaid means extending, inside c said prongs, said: meansextending through saidslot de- :tacl ablyholding said tooth and shank inengagement with,

each otherand in'which 'saidmeans comprises cooperat tag means on ,saidto'othqand shank to restrain dislodg-; j ment ,of said tooth fromsaidshank; said shank being f fformedwithastep shaped to receive a part orthe proxy a ,irnal; end of saidl tooth and the portion of said shankformed with said, step is also formed'witli an apertureoy I ,and saidlast-mentioned means comprises fastening means f extending through saidslot and aperture in said shank todraw said tooth toward said shank toengage said co ioperatingmeanswhen said fastening means is operative,a'nd'to permit disengagement of said cooperating means I,when-s'aidtastening means is inoperative, said slot 'exntendingsubstantially. forwardof said aperture, and a first protuberanceon said shank extendingup into said slot 4 =between saidfasteningmeansand the forward end of- *saidslot;

fitfinto said sidedepressionsg t ReferencesCi'ted in the'file ofthispatent I, i V

UNITED STATES PATENTS Long "in; Sept; 3, 1878' a Gasman can; 1911: I

